Objective: To compare the effectiveness of prostaglandin E 2 intravaginal gel with the intracervical gel in patients with an unfavorable cervix. Method: In a prospective multicenter trial 470 patients with unfavorable Bishop scores (3-4) were randomized to receive prostaglandin vaginal gel (2 mg) or intracervical gel (0.5 mg). Results: In patients with unfavorable Bishop scores the intravaginal application route resulted in a better cervical ripening, a shorter induction to delivery interval and a higher cumulative rate of deliveries during 24 h (P=0.01). Conclusion: Intravaginal instillation of prostaglandin E 2 gel for induction of labor is effective in patients with an unfavorable Bishop score of 3-4.